The Blackbearing B3 Bottom Bracket Bearing Kit is specially designed to deliver precision, durability and smooth performance for Truvativ GXP ALT cranksets. Crafted to withstand bottom bracket stresses, it ensures consistent power transfer and long-lasting reliability.

Complete Dual-Bearing Kit: This kit includes two high-quality bearings — 6805-2RS (25x37x7) and MR22237-2RS (22.2x37x7/11.5). Together, they provide the exact fit and balance required for GXP crank systems, ensuring efficient rotation and reduced friction through every pedal stroke.

Optimized for Bottom Bracket Demands: Built to handle the unique loads and lateral forces within bottom bracket assemblies, the B3 bearing set offers exceptional smoothness and resistance to wear. Each bearing is precision-machined to deliver seamless alignment and dependable performance.

Double Sealed for Protection: Both bearings feature a 2RS double-seal design that keeps out moisture, dirt and debris, maintaining clean lubrication and extending bearing life. This ensures quiet operation and reduced maintenance over time.

Developed using premium-grade materials and tested under real cycling conditions, the Blackbearing B3 Bottom Bracket Bearing Kit provides superior efficiency, longevity and a perfectly balanced pedaling experience for Truvativ GXP ALT setups.

Features

• Complete Dual-Bearing Kit: Includes two precision bearings — 6805-2RS (25x37x7) and MR22237-2RS (22.2x37x7/11.5) — for optimal fit and rotation balance.
• Optimized for Bottom Bracket Loads: Engineered to handle axial and lateral forces within GXP systems, ensuring smooth power transfer and minimal drag.
• Durable, High-Quality Construction: Manufactured with premium materials to resist deformation and wear under heavy pedaling conditions.
• Double-Sealed Protection: 2RS seals on both bearings prevent dirt and moisture intrusion, maintaining clean lubrication for extended performance.
• Reliable, Long-Term Operation: Designed and tested to deliver long-lasting smoothness, consistency and durability in real-world cycling conditions.

Specifications 

• Product Number: BB-GXPALT-B3
• Seal Type: Double Sealed (2RS)
• Compatibility: Truvativ GXP ALT Cranksets
• Bearing Type: 6805-2RS + MR22237-2RS
• Dimensions: 25x37x7 mm & 22.2x37x7/11.5
• Bearing Inner Diameter: 25 mm | 22.2 mm
• Bearing Outer Diameter: 37 mm | 37mm
• Width: 7 mm | 7/11.5 mm